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Message-ID: <tencent_856E1C97CCE9E2ED66CC087B526CD42ED50A@qq.com>
Date: Sun, 5 Nov 2023 10:12:08 +0800
From: Edward Adam Davis <eadavis@...com>
To: richardcochran@...il.com
Cc: davem@...emloft.net,
habetsm.xilinx@...il.com,
jeremy@...ine.org,
linux-kernel@...r.kernel.org,
netdev@...r.kernel.org,
reibax@...il.com,
syzbot+df3f3ef31f60781fa911@...kaller.appspotmail.com
Subject: [PATCH net-next V6] ptp: fix corrupted list in ptp_open
There is no lock protection when writing ptp->tsevqs in ptp_open() and
ptp_release(), which can cause data corruption, use spin lock to avoid this
issue.
Moreover, ptp_release() should not be used to release the queue in ptp_read(),
and it should be deleted together.
Reported-and-tested-by: syzbot+df3f3ef31f60781fa911@...kaller.appspotmail.com
Fixes: 8f5de6fb2453 ("ptp: support multiple timestamp event readers")
Signed-off-by: Edward Adam Davis <eadavis@...com>
---
drivers/ptp/ptp_chardev.c | 11 +++++++----
drivers/ptp/ptp_clock.c | 1 +
drivers/ptp/ptp_private.h | 1 +
3 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 282cd7d24077..31594f40a21e 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -108,6 +108,7 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
container_of(pccontext->clk, struct ptp_clock, clock);
struct timestamp_event_queue *queue;
char debugfsname[32];
+ unsigned long flags;
queue = kzalloc(sizeof(*queue), GFP_KERNEL);
if (!queue)
@@ -119,8 +120,10 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
}
bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
spin_lock_init(&queue->lock);
+ spin_lock_irqsave(&ptp->tsevqs_lock, flags);
list_add_tail(&queue->qlist, &ptp->tsevqs);
pccontext->private_clkdata = queue;
+ spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
/* Debugfs contents */
sprintf(debugfsname, "0x%p", queue);
@@ -139,13 +142,15 @@ int ptp_release(struct posix_clock_context *pccontext)
{
struct timestamp_event_queue *queue = pccontext->private_clkdata;
unsigned long flags;
+ struct ptp_clock *ptp =
+ container_of(pccontext->clk, struct ptp_clock, clock);
if (queue) {
debugfs_remove(queue->debugfs_instance);
+ spin_lock_irqsave(&ptp->tsevqs_lock, flags);
pccontext->private_clkdata = NULL;
- spin_lock_irqsave(&queue->lock, flags);
list_del(&queue->qlist);
- spin_unlock_irqrestore(&queue->lock, flags);
+ spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
bitmap_free(queue->mask);
kfree(queue);
}
@@ -585,7 +590,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
free_event:
kfree(event);
exit:
- if (result < 0)
- ptp_release(pccontext);
return result;
}
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 3d1b0a97301c..ea82648ad557 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -247,6 +247,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
if (!queue)
goto no_memory_queue;
list_add_tail(&queue->qlist, &ptp->tsevqs);
+ spin_lock_init(&ptp->tsevqs_lock);
queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
if (!queue->mask)
goto no_memory_bitmap;
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 52f87e394aa6..63af246f17eb 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -44,6 +44,7 @@ struct ptp_clock {
struct pps_device *pps_source;
long dialed_frequency; /* remembers the frequency adjustment */
struct list_head tsevqs; /* timestamp fifo list */
+ spinlock_t tsevqs_lock; /* one process at a time writing the timestamp fifo list*/
struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
wait_queue_head_t tsev_wq;
int defunct; /* tells readers to go away when clock is being removed */
--
2.25.1
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